TW201627442A - Polarizing plate having protective layer and display device comprising the same - Google Patents

Abstract

A polarizing plate includes an adhesive layer, a protective layer made of an aqueous composition containing polyvinylalcohol, and a polarizer which are laminated in this order, and the polarizer includes a liquid crystal coating layer which is formed on one surface of a base film thereof. The polarizing plate having the above configuration may exhibit increased durability and maintain optical characteristics, and thereby implementing high image quality in the display device with increased durability.

Description

Protective layer polarizing plate and display device therewith

The present invention relates to a polarizing plate which is excellent in durability and has little change in optical properties, and a display device including the polarizing plate.

In recent years, with the development of optical technology, in place of the conventional image tube, a technology using various types of displays such as a plasma display (PDP), a liquid crystal display (LCD), and an organic/inorganic EL display (ELD) has been proposed and commercially available. These display devices propose to utilize various plastic films, and their required performance has become increasingly high in recent years. For example, in the case of a liquid crystal display, various plastic films are used for a polarizing plate, a retardation film, a plastic substrate, a light guide plate, and the like in order to reduce the thickness, weight, and display characteristics. The polarizing plate is an optical element that polarizes in a specific direction in order to make natural light or arbitrary polarized light. The non-polarized light emitted from the light source of the display device, only the light that is subjected to the linearly polarized light through the polarizing plate is incident on the liquid crystal cell, and the transmitted light is adjusted by the degree of rotation of the polarization axis of the incident light. Intensity, which can represent the gray scale between black and white. In summary, the polarizing plate is one of the core materials that can be visually confirmed by an image realized by the flat panel display device. In general, the polarizing plate has a configuration in which a polarizer is laminated with a triacetyl cellulose film (hereinafter also referred to as a TAC film) as a protective film, and the polarizer is made by iodine. Or a polyvinyl alcohol film dyed with a dichroic dye, which is stretched in a certain direction and bridged. However, the polyvinyl alcohol film as a polarizer and the TAC film as a protective film for a polarizer have characteristics in which the film itself is not resistant to humidity, and heat resistance and moisture resistance are insufficient due to manufacturing steps such as stretching. Therefore, if the polarizing plate composed of the films is used for a long period of time in a high-temperature or high-humidity atmosphere, the degree of polarization is lowered, and the polarizer is separated from the protective film, or the optical characteristics are lowered, so that the use is limited. Further, the TAC film changes depending on the surrounding temperature/humidity environment, and the in-plane phase difference (R _in ) and the thickness direction phase difference (R _th ) vary drastically, especially for incident light from an oblique direction, phase. The difference has changed a lot. Therefore, when a polarizing plate containing a TAC film as a protective film is applied to a liquid crystal display device, the viewing angle characteristics change depending on the ambient temperature/humidity environment, and the image quality is lowered. Further, since the value of the photoelastic coefficient of the TAC film is also large, the durability of the heat-resistant and moist-resistant environment is evaluated, and the phase difference characteristic changes locally, and the image quality is liable to lower. As a material for replenishing the disadvantages of the TAC film, methacryl-based resins are well known. However, it is known that the methacrylic resin is easily damaged or cracked, so that problems occur in the production or handling of the polarizing plate, and productivity is lowered. Further, since an acrylate resin is used as the material of the film, a casting method must be used, and thus the manufacturing method is complicated, and the cost rises. The adhesive is used to bond the polarizer and the protective film, and specifically includes an acrylic UV-type adhesive, a dry lamination adhesive mixed with a urethane resin solution and a polyisocyanate resin solution, and a styrene butadiene rubber. An adhesive, an epoxy-based adhesive, a polyvinyl alcohol-based adhesive, a urethane-based adhesive, an adhesive containing a polyester-based ionic polymer (ionomer) type urethane resin, and a compound having an oxidized glycidyl group, and heat Hardening type of adhesive, etc. In the case of such an adhesive, in the case of a water-based adhesive, since the adhesion force is restricted by the protective film material, alkali treatment, corona treatment, or the like is further applied to the surface of the protective film. Further, when the materials of the protective film are different, problems such as curling of the polarizing plate and deterioration of initial optical properties due to the drying step occur. Therefore, in order to complement the shortcomings of the water-based adhesive, a non-aqueous adhesive has been developed. However, if a non-aqueous adhesive is used as a heat or photocurable adhesive, an additional hardening step is required, and in particular, photohardening sometimes causes damage to the polarizing plate. Further, in general, since the viscosity of the non-aqueous adhesive is high, the thickness of the formed adhesive layer is increased. Therefore, wrinkles are generated in the polarizing plate, or problems such as breakage of the polarizing plate occur due to an increase in brittleness. Korean Patent No. 10-1459126 (Patent Document 1) discloses an adhesive composition which exhibits little change due to heat and humidity between the polarizer and the protective film and exhibits excellent adhesion. The adhesive composition used at this time contains a polyvinyl alcohol resin, a zirconium compound, and an imide type bridging agent, so that the durability and water resistance of the polarizing plate are improved. Japanese Laid-Open Patent Publication No. 2004-334168 (Patent Document 2) discloses a polarizing plate which is laminated with a cyclic olefin via a binder containing a urethane-based adhesive and a polyvinyl alcohol-based resin in a polyvinyl alcohol-based polarizer. A protective film composed of a resin. However, the cycloolefin resin is easily corroded by an organic solvent such as acetone, toluene or ethyl acetate. Since such an organic solvent is used for the production of a non-aqueous adhesive, it may remain in the adhesive. In Patent Documents 1 and 2, the problem of deterioration in durability of the polarizing plate caused by the adhesive or the protective film can be solved to some extent, but the effect is not sufficient. Further, in recent years, there have been limitations on materials and methods for polarizing plates that have been required for display devices to be thinner and lighter. On the other hand, it is confirmed that a polarizer is produced by applying a liquid crystal compound which exhibits polarizing characteristics to a base film, and the polyvinylidene is not used, and it is not used in the case of the above-mentioned Japanese Patent Publication No. 2013-0008466 (Patent Document 3). The extension step can completely solve the aforementioned problems. However, since the polarizing layer sometimes deteriorates in the manufacturing stage or the use stage due to the external environment, it is necessary to form a protective layer on the polarizing layer. Japanese Laid-Open Patent Publication No. 2004-334168 (Patent Document 3).

DISCLOSURE OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION In order to produce a polarizing plate having high water resistance and heat resistance and having a protective film capable of maintaining optical properties stably, the present inventors have earnestly accumulated research and found that it is composed of a water system containing polyvinyl alcohol. To form a protective layer of the polarizing plate, the optical performance can be effectively protected by a simple step even without an adhesive or another protective film. Further, when a polarizing film is produced by applying a liquid crystal compound which exhibits polarizing characteristics to a base film, since the elongation is not caused without extending the step, it is confirmed that the above problems can be solved, and the present invention has been completed. Accordingly, an object of the present invention is to provide a polarizing plate which has little change in optical characteristics and which can ensure excellent durability. Another object of the present invention is to provide a display device including the foregoing polarizing plate. Means for Solving the Problems In order to achieve the above object, the present invention provides a polarizing plate characterized by sequentially laminating an adhesive layer, a protective layer and a polarizer; the protective layer is formed of a water-based composition containing polyvinyl alcohol. . In this case, the polyvinyl alcohol is contained in an amount of 1 to 10% by weight based on 100% by weight of the total of the aqueous composition. It is characterized in that the protective layer is formed by applying a water-based composition and drying it. Further, the dried layer has a thickness of 0.5 to 3.0 m after drying. Further, the polarizer is attached to one surface of the base film to form a liquid crystal coating layer which is imparted with an orientation by a non-extension method. The method is characterized in that the polarizing plate is subjected to high temperature or high humidity, and the change in the transmittance before and after the placement is 1.0% or less. Further, the polarizing plate is characterized in that the polarizing plate is subjected to high temperature or high humidity, and the amount of change in the degree of polarization before and after the placement is 1.0% or less. The present invention is a display device comprising the polarizing plate. EFFECT OF THE INVENTION The polarizing plate of the present invention can solve the problem of deterioration in optical performance by a protective layer which is formed of a water-based composition containing polyvinyl alcohol. Further, the polarizing plate can solve the problem of reduced durability due to the manufacturing steps. Further, the polarizing plate described above can be applied to various display devices to achieve a high level of image quality.

MODE FOR CARRYING OUT THE INVENTION The present invention provides a polarizing plate which has improved wet heat durability and a small change in optical characteristics. The polarizer is made of a hydrophilic resin such as polyvinyl alcohol, and generally exhibits characteristics that are not tolerant to moisture. Further, in the production, an extension step is applied to impart polarizing performance. However, the stretching is performed under conditions of high temperature or humidification, and thus deformation such as shrinkage or breakage is likely to occur, resulting in deterioration of durability and optical characteristics of the polarizing plate. Since the polarizer laminates the protective film, the physical properties of the polarizing plate can be maintained to some extent. However, the adhesion of the protective film requires an adhesive having excellent adhesion to both the polarizer and the protective film. Although various types of adhesives are used as described above, the thickness of the polarizing plate increases, the appearance is poor, and the performance is lowered due to an increase in the number of laminations and a change in the physical properties of the adhesive force. On the other hand, the present invention solves the aforementioned problems by forming a protective layer from a mixture of water and polyvinyl alcohol so that the polarizer is coated with a liquid crystal coating on one side of the base film. The invention will be described in detail below with reference to the drawings. However, the drawings attached to the present specification are merely illustrative of the invention and are not intended to limit the invention. Furthermore, in the drawings, for the sake of explanation, some of the constituent elements may be emphasized, reduced, or omitted. Fig. 1 is a cross-sectional view showing a polarizing plate of an example of the present invention. Referring to Fig. 1, a polarizing plate 100 of the present invention has a structure in which an adhesive layer 10, a protective layer 20, and a polarizer 30 are laminated in this order. At this time, the protective layer 20 is formed on the polarizer 30, and is formed of a water-based composition containing polyvinyl alcohol to maintain optical properties, and the polarizer formed by the coating step is blocked from the external environment to protect it. The function. Specifically, the protective layer 20 prevents the optical performance such as the transmittance and the degree of polarization of the polarizer from being lowered. Further, since the protective layer 20 replaces the protective film and the adhesive used in the conventional polarizing plate, the thickness of the polarizing plate can be reduced. The aforementioned water-based composition contains polyvinyl alcohol and water. Polyvinyl alcohol is an ethylene-based polymer, and has excellent adhesion. The repeating unit of the polymer has a hydroxyl group, exhibits hydrophilicity, is chemically very stable, and is easily bridged to form a network, so that the surface coating is easy. Therefore, the polyvinyl alcohol which can be used is not particularly limited as long as it can be sufficiently applied to the polarizer, and the optical perspective is excellent, and there is no change such as yellowing or the like. For example, a polyvinyl alcohol obtained by alkalizing polyvinyl acetate; a derivative thereof; and an alkali compound of a copolymer of a monomer copolymerizable with vinyl acetate; and an acetal of polyvinyl alcohol Modified polyvinyl alcohol, such as ureification, urethane, etherification, grafting, and phosphation. Examples of the monomer include unsaturated carboxylic acids such as maleic acid (anhydride), fumaric acid (anhydride), crotonic acid, itaconic acid, and (meth)acrylic acid, and esters thereof; styrene; A-olefin such as propylene; (meth)allylsulfonic acid (sodium base), sodium sulfonate base (monoalkyl malate), sodium disulfonate base malate, N-hydroxymethyl decylamine And a decylamine sulfonate base salt, an N-vinyl fluorenone, an N-vinyl quinone ketal derivative, and the like. These polyvinyl alcohols may be used alone or in combination of two or more. The polyvinyl alcohol may be used in an amount of 1 to 10% by weight, and more preferably 2 to 5% by weight based on 100% by weight of the total of the aqueous composition. If it is less than the above range, the protective effect of the polarizer may be insufficient, and if it exceeds the above range, the problem of lowering coatability or stability may occur. The water-based composition forming the protective layer 20 of the present invention can form a uniform layer by using water as a solvent, and is also very suitable from the viewpoint of coatability and stability. Further, in terms of the formation of the layer, the water of the solvent can be easily removed by drying, so that the step is very economical. The water-based composition may further include a plasticizer, a decane coupling agent, an antistatic agent, a leveling agent, an alkaline substance, etc. which are generally used in the field, as long as the effect of the present invention is not impaired as needed. additive. The protective layer 20 is formed by a method in which the water-based composition is applied and dried. The coating method may be a method generally employed in the field, and examples thereof include an extrusion coating method, a direct gravure coating method, a reverse gravure coating method, a CAP coating method, a compression molding method, and a dip coating method. Method, bar coating method and spin coating method. The drying is carried out by, for example, thermal drying, and the drying temperature is suitably selected in the range of 50 to 200 ° C, more preferably 80 to 150 ° C. The drying time is preferably from 1 to 5 minutes. If the temperature and time range are exceeded, the problem of a decrease in coating quality may occur. The thickness of the dried layer of the protective layer 20 is 0.5 to 3.0. m m, more preferably 0.7 to 1.5 m m. The thickness of the foregoing protective layer 20 is less than 0.5 m m, can not get the effect as a protective layer, if it exceeds 3.0 m m, which easily causes a problem of poor appearance of the polarizing plate. The polarizer 30 used in the polarizing plate of the present invention is applied to one surface of the base film 30b, and is coated with an alignment liquid crystal coating layer 30a by a non-extension method, since the stretching step is not applied by the conventional polarizing plate. Therefore, it is possible to improve the reduction in durability and the deterioration of optical characteristics such as the transmittance and the degree of polarization accompanying this. The base film 30b can be used without limitation, and generally used for a transparent film for optics. Among them, transparency, mechanical strength, thermal stability, moisture shielding, phase difference uniformity, and equivalence are preferably used. Film. A transparent polymer film can be used as the material of the base film 30b. Specifically, a polyolefin resin, a polyester resin, a cellulose resin, a polycarbonate resin, an acrylic resin, a styrene resin, a vinyl chloride resin, a guanamine resin, or a quinone may be used. Resin, polyether oxime resin, oxime resin, polyether oxime resin, polyether ether ketone resin, polyphenylene sulfide resin, vinyl alcohol resin, polydivinylidene resin, vinyl condensate A selected from the group consisting of an aldehyde resin, a polyarylate resin, a polyoxymethylene resin, and an epoxy resin. More preferably used from cellulose triacetate (TAC), polyacrylate (PAC), polyethylene terephthalate (PET), polycarbonate (PC), polyethylene (PE), raw spinel derivatives, And one selected from the group consisting of the combinations of the resins. By using the base film 30b, it is possible to prevent damage during manufacturing, transportation, and storage of the polarizing plate, and it is easy to handle. The thickness of the base film 30b is not limited to a specific range, and is generally used, for example, from 5 to 100. m m, it is better to use 15~60 m A substrate film of m. The thickness of the base film 50a is less than 5 m m, the mechanical strength of the film sometimes decreases, if it exceeds 100 m m, it will hinder the thinning, so it is not suitable. The liquid crystal coating layer 30a is produced by coating a composition for a liquid crystal coating layer on one surface of the base film 306. The composition for a liquid crystal coating layer contains a polymerizable liquid crystal compound and a dichroic dye. The polymerizable compound refers to a compound having a liquid crystal phase by including a terminal group polymerizable with a mesogen capable of exhibiting liquid crystallinity. When the compound is polymerized, a polymer film which maintains the liquid crystal phase in which the liquid crystals are aligned and which has been bridged can be obtained. The liquid crystal phase arranged in a certain direction functions to convert the natural light incident from the outside into a desired single state. Further, the film formed by the end rib bridge which can be so polymerized maintains the formed liquid crystal phase and has a solid film form, and thus is mechanically stable or thermally stable. The polymerizable liquid crystal compound is a polymerizable liquid crystal compound which exhibits a smectic phase. The smectic phase includes a smectic A phase, a smectic B phase, a smectic D phase, a smectic E phase, a smectic F phase, a smectic G phase, a smectic H phase, a smectic phase I phase, and a smectic phase J phase And the layer K phase. Among them, the layer B phase, the layer F phase and the layer I are particularly suitable, and the layer B phase is more suitable. When the liquid crystal phase of the polymerizable liquid crystal compound is such a liquid crystal phase, an optical film having a high degree of alignment can be obtained. The polymerizable liquid crystal compound may, for example, be a compound represented by the following formula (1). [Chemical 1] U ¹ -V ¹ -W ¹ -X ¹ -Y ¹ -X ² -Y ² -X ³ -W ² -V ² -U ² (1) [in formula (1), X ¹ , X ² And X ³ It means a para-phenyl group which may have a substituent, or a cyclohexane-1,4-diyl group which may have a substituent. Where X ¹ , X ² And X ³ At least one of them represents a para-phenyl group which may also have a substituent. Y ¹ And Y ² Respectively -CH ₂ CH ₂ -, -CH ₂ O-, -COO-, -OCOO-, single bond, -N=N-, -CR ^a =CR ^b -, -C≡C- or -CR ^a =N-. R ^a And R ^b Each represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. U ¹ It represents a hydrogen atom or a polymerizable group. U ² Indicates a polymerizable group. W ¹ And W ² Each represents a single bond, -O-, -S-, -COO- or -OCOO-. V ¹ And V ² Each represents an alkanediyl group having 1 to 20 carbon atoms which may have a substituent, and -CH contained in the alkanediyl group ₂ - may also be substituted by -O-, -S- or -NH-. ] X ¹ , X ² And X ³ Each is a para-phenyl group which may also have a substituent, or a cyclohexane-1,4-diyl group which may have a substituent. Where X ¹ , X ² And X ³ At least one of them may also be a 1,4-phenylene group having a substituent. More suitable X ¹ , X ² And X ³ At least two of them are a pendant phenyl group having a substituent. It is more suitable for the phenylene group to be unsubstituted. The aforementioned cyclohexane-1,4-diyl group is more preferably a cyclohexane-1,4-diyl group, and these are preferably unsubstituted. Examples of the substituent which the phenylene group may have include an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group or a butyl group, a cyano group and a halogen group (halogen atom). The cyclohexane-1,4-diyl group may have a substituent, and examples thereof include an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, and a butyl group, a cyano group, and a halogen group (a halogen atom). Cyclohexane-1,4-diyl-CH ₂ - may also be substituted by -O-, -S- or -NR-. In this case, R is an alkyl group having 1 to 6 carbon atoms or a phenyl group. Y ¹ And Y ² Each is -CH ₂ CH ₂ -, -CH ₂ O-, -COO-, -OCOO-, single bond, -N=N-, -CR ^a =CR ^b -, -C≡C- or -CR ^a =N-. The key positions of the bases can be in any direction. Y ¹ More preferably -CH ₂ CH ₂ -, -COO- or single button, Y ² More preferably -CH ₂ CH ₂ -or-CH ₂ O-. R ^a And R ^b Each represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Examples of the alkyl group having 1 to 4 carbon atoms include a methyl group, an ethyl group, and a butyl group. U ¹ It represents a hydrogen atom or a polymerizable group, and is more preferably a polymerizable group. U ² Indicates a polymerizable group. Examples of the polymerizable group include a vinyl group, a vinyloxy group, a 1-chlorovinyl group, an isopropenyl group, a 4-vinylphenyl group, an acryloxy group, a methacryloxy group, an oxirane group, and an oxirane group. Butyl and the like. Among them, an acryloxy group, a methacryloxy group, an oxiranyl group and an oxetanyl group are preferable, and a propylene fluorenyl group is more preferable. At this time, U ¹ And U ² More preferably, they are the same kind of polymerizable group. W ¹ And W ² Each is a single bond, -O-, -S-, -COO- or -OCOO-, more preferably a single bond or -O-. V ¹ And V ² Each is an alkanediyl group having 1 to 20 carbon atoms which may have a substituent, and -CH contained in the alkanediyl group ₂ - may also be substituted by -O-, -S- or -NH-. Examples of the alkylene group having 1 to 20 carbon atoms include a methylene group, a vinyl group, a propane-1,3-diyl group, a butane-1,3-diyl group, a butane-1,4-diyl group, and a pentane. -1,5-diyl, hexane-1,6-diyl, heptane-1,7-diyl, octane-1,8-diyl, decane-1,10-diyl, fourteen Alkyl-1,14-diyl and eicosane-1,20-diyl and the like. More preferably, it is an alkanediyl group having 2 to 12 carbon atoms, more preferably an alkanediyl group having 6 to 12 carbon atoms. The alkanediyl group may have a substituent, and examples thereof include a cyano group and a halogen group (halogen atom). The specific compound represented by the above formula (1) is as follows. [Chemical 2] The polymerizable liquid crystal compound used in the present invention is not limited to the above examples, and any of the polymerizable liquid crystal compounds known in the art can be used if the above conditions are satisfied. The dichroic dye is a dye which is contained in the liquid crystal coating composition of the present invention and which has polarizing characteristics and has a property of absorbance in the long-axis direction of the molecule and absorbance in the short-axis direction. The dichroic dye may be a dye or a pigment, and the present invention is not particularly limited. The dichroic dye is conventionally used as a dichroic dye having a maximum absorption wavelength at 300 to 700 nm, and any of them can be used. As the dichroic dye, one selected from the group consisting of acridine dye, oxazine dye, cyanine dye, naphthalene dye, azo dye, anthraquinone dye, and the like can be used. The azo dye is more preferably a monoazo dye, a disazo dye, a trisazo dye, a tetrazolium dye or a stilbene azo dye. The content of the dichroic dye is preferably 50 parts by weight or less, more preferably 0.1 to 20 parts by weight, even more preferably 0.1 to 10 parts by weight, based on 100 parts by weight of the polymerizable liquid crystal compound. When it is in the above range, it is possible to polymerize without distorting the alignment of the polymerizable liquid crystal compound. When the content of the dichroic dye exceeds 50 parts by weight, the alignment of the polymerizable liquid crystal compound may be disturbed. The liquid crystal coating composition may further contain a leveling agent, a polymerization initiator, and a solvent in order to ensure the efficiency of the coating step and the uniformity of the coating layer. The leveling agent serves to adjust the fluidity of the composition for liquid crystal coating to make the film flat. As the leveling agent, a leveling agent selected from the group consisting of a leveling agent containing a polyacrylate compound as a main component, a leveling agent containing a fluorine atom-containing compound as a main component, and a combination of the above may be used. . Specific examples of the leveling agent containing a polyacrylate compound as a main component include BYK-350, BYK-352, BYK-353, BYK-354, BYK-355, BYK-358N, BYK-361N, and BYK-380. , BYK-381, BYK-392 (the above is BYK Chemie) and so on. The leveling agent containing a fluorine atom-containing compound as a main component may, for example, be MEGAFACE R-08, MEGAFACE R-30, MEGAFACE R-90, MEGAFACE F-410, MEGAFACE F-411, MEGAFACE F-443, MEGAFACE F-445, MEGAFACE F-470, MEGAFACE F-471, MEGAFACE F-477, MEGAFACE F-479, MEGAFACE F-482, MEGAFACE F-483 (above, DIC Corporation), SURFLON S-381, SURFLON S-382, SURFLON S-383, SURFLON S-393, SURFLON SC-101, SURFLON SC-105, KH-40, SA-100 (above (the above is manufactured by AGC SEIMI CHEMICAL Co., Ltd.), E1830, E5844 (above is DAIKIN Fine Chemicals Co., Ltd.), EFTOP EF301, EFTOP EF303, EFTOP EF351, EFTOP EF352 (above, manufactured by Mitsubishi Materials Electronic Chemicals Co., Ltd.), etc. The content of the leveling agent is 0.3 to 5 by weight based on 100 parts by weight of the polymerizable liquid crystal compound. More preferably, it is 0.5 to 3 parts by weight. When the content of the leveling agent is within the above range, the components contained in the composition for liquid crystal coating can be easily aligned horizontally, and the obtained liquid crystal coating layer tends to be smooth. If the content of the dye exceeds 5 parts by weight, the liquid crystal coating capacity The polymerization initiator is a compound which starts polymerization of a polymerizable liquid crystal compound, and generates active radicals by light and/or heat, and particularly a polymerization initiator which generates an active radical or an acid by light. The photopolymerization initiator is not particularly limited, and a general photoradical initiator can be used without limitation, and examples thereof include an acetophenone-based compound, a benzoin-based compound, and An benzophenone-based compound, a triazine-based compound, an anthraquinone-based compound, a thioxanthone-based compound, an anthraquinone-based compound, etc. Examples of the acetophenone-based compound include diethoxyacetophenone and 2-hydroxy-2-methyl. 1-phenylpropan-1-one, benzyldimethylketal, 2-hydroxy-1-[4-(2-hydroxyethoxy)phenyl]-2-methylpropan-1-one, 1-hydroxycyclohexyl benzophenone, 2-methyl-1-(4-methylthiophenyl)-2-morpholinepropan-1-one, 2-benzyl-2-dimethylamine-1-(4 Oligomer of morpholine phenyl)butan-1-one, 2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propan-1-one. The compound may be benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, ampere Hong isobutyl ether and the like. Examples of the benzophenone-based compound include benzophenone, o-benzoic acid methyl, 4-phenylbenzophenone, 4-benzoquinone-4'-methyldiphenyl sulfide, and 3,3'. , 4,4'-tetrakis (tertiary butyl peroxycarboxyl) benzophenone, 2,4,6-trimethylbenzophenone, 4,4'-di(N,N'-dimethylamine ) - benzophenone and the like. The triazine-based compound may, for example, be 2,4-bis(trichloromethyl)-6-(4-methoxyphenyl)-1,3,5-triazine or 2,4-bis(trichloromethyl). -6-(4-methoxynaphthyl)-1,3,5-triazine, 2,4-bis(trichloromethyl)-6-piperidin-1,3,5-triazine, 2,4 - bis(trichloromethyl)-6-(4-methoxystyryl)-1,3,5-triazine, 2,4-bis(trichloromethyl)-6-[2-(5- Methylfuran-2-yl)vinyl]-1,3,5-triazine, 2,4-bis(trichloromethyl)-6-[2-furan-2-yl)vinyl]-1, 3,5-triazine, 2,4-bis(trichloromethyl)-6-[2-(4-diethylamine-2-methylphenyl)vinyl]-1,3,5-triazine 2,4-bis(trichloromethyl)-6-[2-(3,4-dimethoxyphenyl)vinyl]-1,3,5-triazine, and the like. Examples of the oxime compound include 2-ethyl hydrazine, octamethyl hydrazine, 1,2-benzopyrene, and 2,3-diphenyl hydrazine. Examples of the thioxanthone-based compound include 2-isopropylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone, 1-chloro-4-propoxythioxanthone, and the like. . The lanthanoid compound may be exemplified by 9,10-dimethoxy oxime, 2-ethyl-9,10-dimethoxy oxime, 9,10-diethoxy oxime, 2-ethyl-9,10-diethoxy Hey. The thermal radical initiator is, for example, a peroxide compound or an azo compound, but is not limited thereto. As the azo compound, 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(isobutyronitrile), 2,2'-azobis (2,4-) can be used. Dimethylvaleronitrile) and 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile) and the like. Examples of the peroxide-based compound include tetramethylbutyl peroxy neodecanoate, bis(4-butylcyclohexyl)peroxydicarbonate, and di(2-ethylhexyl)peroxycarbonate. Oxidized neobutyl phthalate, dipropyl peroxydicarbonate, diisopropyl peroxydicarbonate, diethoxyethyl peroxydicarbonate, diethoxyhexyl peroxydicarbonate, hexyl peroxydicarbonate , dimethoxybutyl peroxydicarbonate, bis(3-methoxy-3-methoxybutyl)peroxydicarbonate, dibutyl peroxydicarbonate, dihexadecyl peroxydicarbonate, peroxidation Tetrafluorocarbonate, 1,1,3,3-tetramethylbutyl peroxypivalate, hexyl peroxypivalate, butyl peroxypivalate, trimethylhexyl peroxide, Peroxidic neomethyl hydroxybutyl phthalate, peroxy neodecanoate, butyl peroxy neodecanoate, tertiary butyl peroxy neoheptanoate, ammonium peroxypivalate, transoxidation Tertiary acid butyl ester, tertiary alkylamino-2-hexanyl ethyl ester, laurel laurel, dilaurin peroxide, cerium peroxide, benzammonium peroxide or benzoic acid peroxide , But is not limited to such compounds. The content of the polymerization initiator is preferably 0.1 to 30 parts by weight, more preferably 0.5 to 10 parts by weight, even more preferably 0.5 to 8 parts by weight, based on 100 parts by weight of the polymerizable liquid crystal compound. Within the above range, the polymerization reaction can be promoted without hindering the alignment of the polymerizable liquid crystal compound. The solvent is a solvent which is suitable for dissolving the components of the liquid crystal coating composition, and is preferably inert to the polymerization reaction of the polymerizable liquid crystal composition. Examples of the solvent include alcohol solvents such as methanol, ethanol, ethylene glycol, isopropanol, propylene glycol, ethylene glycol methyl ether, ethylene glycol butyl ether, and propylene glycol monomethyl ether; ethyl acetate, butyl acetate, and ethylene glycol; Methyl ether acetate, g - ester solvent such as butyrolactone, propylene glycol methyl ether acetate, ethyl lactate; ketone solvent such as acetone, methyl ethyl ketone, cyclopentanone, 2-heptanone, methyl isobutyl ketone; pentane, An aliphatic hydrocarbon solvent such as an alkane or a heptane; an aromatic hydrocarbon solvent such as toluene or xylene; a nitrile solvent such as acetonitrile; an ether solvent such as tetrahydrofuran or dimethoxyethane; or a chlorine-containing solvent such as chloroform or chlorobenzene. These solvents may be used singly or in combination of two or more. This solvent is used as a residual portion with respect to 100 parts by weight of the polymerizable liquid crystal compound, and the content thereof is determined in consideration of the thickness and state of the formed film. Examples of the method for applying the liquid crystal coating composition include an extrusion coating method, a direct gravure coating method, a reverse gravure coating method, a CAP coating method, a die coating method, a dip coating method, and a rod. Coating method and spin coating method. In order to impart alignment properties to the composition for liquid crystal coating of the present invention, a non-extension method such as brushing, annealing or polarized UV irradiation is employed. According to these methods, the polymerizable liquid crystal compound contained in the composition can be uniformly aligned in a desired direction, and the layer can have polarizing characteristics. The brushing method is a method of winding a brushing cloth and placing a rotating brushing roller on a table surface to make it contact with the conveyed film. Annealing is a method in which heat is applied to cause alignment fixing force to appear. Polarized UV irradiation is a method in which light having an arbitrary polarization state is irradiated by a film to exhibit alignment characteristics. Polarized UV irradiation is preferred because of the quality problems associated with brushing or annealing. Next, the liquid crystal coating layer 30a can be obtained by polymerizing the polymerizable liquid crystal compound contained in the film in which the liquid crystal phase has been formed. The polymerization method may be selected depending on the type of the polymerizable group which the polymerizable liquid crystal compound has. When the polymerizable group is a photopolymerizable group, it can be polymerized by a photopolymerization method, and if it is a thermally polymerizable group, it can be polymerized by a thermal polymerization method. As described above, the present invention is preferably a photopolymerization method. In the case of the photopolymerization method, it is not necessary to heat to a high temperature, and therefore a substrate having low heat resistance can be used. The photopolymerization method is carried out by irradiating visible light, ultraviolet light or laser light due to a film in which a liquid crystal phase has been formed. In view of the ease of handling, it is preferable to use ultraviolet light. The light irradiation is performed in a state where the film has formed a liquid crystal phase. As described above, light irradiation may be performed at a temperature at which the liquid crystal phase is displayed. At this time, the pattern can be formed by masking or development or the like. In the present invention, the thickness of the liquid crystal coating layer 30a is preferably 0.3 to 20 m m, more preferably 0.5 to 10 m m, and further preferably 0.5 to 5 m m. Within this range, the polymerizable liquid crystal compound is excellent in the alignment property, and is also easy to form a pattern. In the polarizer of the present invention, an alignment film (not shown) may be formed on the base film 30b. At this time, the composition for liquid crystal coating of the present invention is applied onto the alignment film. The alignment film preferably has a dissolution resistance which is not dissolved by the application of the polymerizable liquid crystal compound of the present invention or the like. Further, it is preferred to have heat resistance for solvent removal or heat treatment for liquid crystal alignment. Further, it is preferably an alignment film which does not cause peeling or the like due to rubbing or the like by brushing. The alignment film preferably contains an alignment polymer or a composition containing an alignment polymer. The above-mentioned alignment polymer may be exemplified by a polyamine or a gelatin having a guanamine bond in the molecule, a polyamidimide having a quinone bond in the molecule, and a polyglycolic acid or polyvinyl alcohol having a hydrolyzate thereof. Alkyl modified polyvinyl alcohol, polyacrylamide, poly A polymer such as azole, polyethyleneimine, polystyrene, polyvinylpyrrolidone, polyacrylic acid or polyacrylate. Among them, polyvinyl alcohol is preferred. These polymers may be used singly or in combination of two or more kinds, or may be copolymerized. Further, these polymers can be easily obtained by polycondensation using dehydration, deamination or the like, or chain polymerization such as radical polymerization, anionic polymerization or cationic polymerization, coordination polymerization or ring-opening polymerization. At this time, the alignment polymer can be applied by dissolving in a solvent. The solvent to be used may, for example, be water; an alcohol solvent such as methanol, ethanol, ethylene glycol, isopropanol, propylene glycol, methyl stilbene, butyl sarbuta or propylene glycol monomethyl ether; ethyl acetate or butyl acetate; Ester, ethylene glycol methyl ether acetate, g An ester solvent such as butyrolactone, propylene glycol methyl ether acetate or ethyl lactate; a ketone solvent such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, methylamino ketone or methyl isobutyl ketone; An aliphatic hydrocarbon solvent such as pentane, hexane or heptane; an aromatic hydrocarbon solvent such as toluene or xylene; a nitrile solvent such as acetonitrile; an ether solvent such as tetrahydrofuran or dimethoxyethane; and a chlorine-substituted carbon such as chloroform or chlorobenzene. Hydrogen solvent. These organic solvents may be used singly or in combination of two or more. Further, in order to form an alignment film, a commercially available alignment film material may be used as it is. Commercially available alignment film materials include SUNEVER (manufactured by Nissan Chemical Industries, Ltd.) and OPTMER (manufactured by JSR Co., Ltd.). When such an alignment film is used, since the unevenness can be reduced, a polarizer having improved environmental resistance or mechanical resistance can be provided. The method of forming the above alignment film is the same as the method of imparting the alignment property of the liquid crystal coating described above. For example, by applying a solution of the above-mentioned alignment polymer or a commercially available alignment film material to the base film, an annealing film can be formed thereon to form an alignment film on the support substrate. The thickness of the alignment film thus obtained is, for example, 10 to 10,000 nm, more preferably 10 to 1,000 nm. Next, the pressure-sensitive adhesive layer 10 is attached to one surface of the protective layer 20 when the polarizing plate produced by the present invention is used for bonding to a panel or the like. When the pressure-sensitive adhesive layer 10 exhibits excellent optical transparency, appropriate wettability, adhesion, adhesion, and the like, it is particularly preferable to use an excellent product such as durability. As the adhesive suitable for forming the pressure-sensitive adhesive layer 10, an acrylic resin, a silicone resin, a rubber resin, a urethane resin, a polyester resin or an epoxy copolymer may be used, and an acrylic copolymer is preferably used. A reduced pressure acrylic adhesive. As the acrylic adhesive, for example, butyl (meth)acrylate, ethyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethyloctyl (meth)acrylate, or the like, (meth)acrylic acid is preferably used. The ester is a resin which is a main constituent unit, or a copolymer resin of two or more kinds of such (meth)acrylates is used. Further, a polar monomer is polymerized in the resins. As the polar monomer, for example, (meth)acrylic acid, 2-hydroxypropyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, decyl (meth)acrylate, 2-N,N-dimethyl A polymerizable compound having a polar functional group such as a carboxyl group, a hydroxyl group, a decylamino group, an amine group or an epoxy group, such as an aminoethyl (meth) acrylate or a glycidyl (meth) acrylate. In other words, in the adhesive, the bridging agent is generally formulated together with the acrylic resin. In this case, the adhesive composition may contain a conventional antistatic agent such as an ionic compound, a conductive polymer, a metal oxide, or a CNT. Antistatic agents are effective in reducing or preventing static electricity generation. The antistatic agent is not particularly limited, and any of the conventional materials can be used. The antistatic agent is preferably an ionic compound, and is an ionic salt which can be composed of an anion or a cation to impart ion conductivity, and is not particularly limited. Specifically, it is preferably an ionic salt comprising: a cation selected from the group consisting of an alkali metal salt, an ammonium salt, a cerium salt, and a cerium salt; and a fluorine-containing inorganic salt, a fluorine-containing organic salt, and iodine An anion selected from the group consisting of ions. In addition, various additives can be formulated in the adhesive. Suitable additives include decane coupling agents. The decane coupling agent is effective for increasing the adhesion to peeling. The method of laminating the above-mentioned adhesive layer 10 on a polarizing plate is not particularly limited as long as it is generally employed in the field. For example, a coating liquid for forming an adhesive layer may be applied to the surface of the protective layer 20, and then dried and laminated. Further, an adhesive layer is formed on the release film of the oxygen-coated coating layer by the same coating method as described above, and the adhesive sheet is produced, and then laminated by a roll press device. In this case, when the adhesive composition contains an ultraviolet curable compound as a bridging agent, it is preferred to apply the adhesive composition or to laminate the ultraviolet rays after lamination using a roll press. The thickness of the adhesive layer 10 can be adjusted by its adhesive force, and generally should be 3 to 100. m m, more preferably 10 to 100 m m. The polarizing plate 100 of the present invention may further laminate a surface treatment layer such as a hard coat layer, an antireflection layer, an antiglare layer, or an antistatic layer as needed. Further, an optical functional film may be further provided by an adhesive or an adhesive. For example, an optical compensation film, a reflective polarization separation film, a retardation film, an anti-glare functional film, a reflection film, a semi-transmissive reflection film, a diffusion control film, a brightness enhancement film, and the like can be given. In particular, the polarizing plate of the present invention forms a protective layer by using a water-based composition containing polyvinyl alcohol, thereby preventing the performance of the polarizing plate from deteriorating due to the conventional use of the protective film and the adhesive of the polarizing plate. Specifically, when a protective film is used, deformation of the protective film itself occurs, and it is disadvantageous in terms of thickness or weight increase due to the additional layer. In addition, the adhesive does not sufficiently satisfy the required characteristics, and changes depending on the use environment of the polarizing plate, and sometimes the polarizing plate is damaged. On the other hand, in the present invention, a water-based composition composed of a mixture of polyvinyl alcohol and water forms a protective layer that does not hinder the optical properties and durability of the polarizing plate, effectively maintains the performance of the polarizer, and is coated by coating. From the standpoint of the simple steps of post-drying, it is very economical. Moreover, since the polarizer included in the polarizing plate structure of the present invention has a liquid crystal coating applied to the base film, it is possible to completely prevent the deterioration of the durability of the polarizer which occurs due to the extension step of the conventional polarizing plate manufacturing step, and The size deformation problem accompanying this. As described above, by the liquid crystal coating layer, the alignment property is imparted by annealing, brushing, light irradiation or the like to have the polarizing characteristics of the polarizer. Therefore, the durability reliability of the polarizer is excellent, and the change in optical characteristics is also small. The polarizing plate of the present invention was confirmed to have a transmittance of 1.0% or less and a change in the degree of polarization before and after being placed in a dry environment at 85 ° C and an environment of 60 ° C and 90% RH for 100 hours, respectively. The present invention provides a display device comprising the aforementioned polarizing plate. The display device is a device having a display element, and the illumination source comprises a light-emitting element or a light-emitting device. The display device may be a liquid crystal display device, an organic electroluminescence (EL) display device, an inorganic electroluminescence (EL) display device, an electron emission display device (for example, a field emission display device (FED), or a surface field emission display device (SED). )), electronic paper (display device using electronic ink or electrophoretic element, plasma display device, projection display device (such as grating light valve (GLV) display device, display device with digital micro-mirror device (DMD)) And a piezoelectric ceramic display device. The liquid crystal display device includes a transmissive liquid crystal display device, a transflective liquid crystal display device, a reflective liquid crystal display device, a direct-view liquid crystal display device, and a projection type liquid crystal display device. A display device for displaying a two-dimensional image, or a stereoscopic display device for displaying a three-dimensional image. In the following, in order to facilitate the understanding of the present invention, a preferred embodiment is presented, but the following embodiments are merely illustrative of the present invention. It is apparent to those skilled in the art that various changes and modifications can be made within the scope of the invention and the scope of the invention. Examples 1 to 5 and Comparative Examples 1 and 2: Production polarizing plate [Example 1] 40 m The m-triacetate (TAC) substrate was coated by a bar coating method and dried at 60 ° C for 1 minute to obtain an alignment film having a thickness of 100 nm. At this time, the composition for the alignment coating layer was a solution obtained by dissolving the following polymer (1-1 or 1-2) having a photoreactive group in cyclopentanone at a concentration of 5% by weight. Using a UV irradiation apparatus (SPOT CURE SP-7, manufactured by USHIO Electric Co., Ltd.), the obtained film was irradiated with light having a intensity of 100 mJ measured at a wavelength of 365 nm, and passed through a wire grid (UIS-27132##, USHIO Motor Co., Ltd.). The polarizing light produced by the company, which gives the alignment performance. Thereafter, the composition for liquid crystal coating was applied by a bar coating method, and dried by heating at 120 ° C for 1 minute, and cooled to room temperature to obtain a dried film. To the obtained film, light having an exposure amount of 1200 mJ (365 nm reference) was irradiated with a UV irradiation device (SPOT CURE SP-7) to obtain a polarizer. In this case, the composition for the liquid crystal coating layer is a weight of 100 parts of the polymerizable liquid crystal compound of the following (2-1), and an azo dye (NKX2029, manufactured by Hayashibara Biochemical Research Institute) as a dichroic dye. 6 parts by weight of 2-methylamino-2-benzyl-1-(4-morpholinylphenyl)butan-1-one (Irgacure 369; manufactured by BASF JAPAN) as a polymerization initiator 2 parts by weight of isopropyl thioxanthone (manufactured by DKSH JAPAN Co., Ltd.) and 1.2 parts by weight of a polyacrylate compound (BYK-361N, manufactured by BYK-Chemie) as a leveling agent, mixed in a solvent ring The pentanone was prepared by stirring the resulting mixture at 80 ° C for 1 hour. [Chemical 3] On the liquid crystal coating layer of the polarizer obtained above, a mixture of polyvinyl alcohol (Z-200, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) and water (3.5:100) was applied, and then dried at 120 ° C for 2 hours to obtain 0.5. m The protective layer of m. Adhesive (LS192NP, manufactured by LINTEC Co., Ltd.) was attached to the protective layer thus formed by using a roll. [Example 2] In addition to Example 1, the thickness of the protective layer after drying was 0.7. m All of m were produced in the same manner as in Example 1. [Example 3] In addition to Example 1, the thickness of the protective layer after drying was 1.5. m All of m were produced in the same manner as in Example 1. [Example 4] A composition of the protective layer of Example 1 was produced in the same manner as in Example 1 except that KL318 (manufactured by Kuraray) was used instead of Z-200 as the polyvinyl alcohol. [Example 5] The same procedure as in Example 1 was carried out except that the composition of the protective layer of Example 1 was changed to a ratio of polyvinyl alcohol:water of 5:100. [Comparative Example 1] The same procedure as in Example 1 was carried out except that the protective layer was not formed in Example 1. [Comparative Example 2] 50 parts by weight of dipentaerythritol hexaacrylate (ARONIX M-403, manufactured by Toagosei Co., Ltd.), 50 parts by weight of acrylic resin (EBECRYL 4858, manufactured by Daicel-UCB Co., Ltd.), and 2- 3 parts by weight of methyl-1[4-(methylthio)phenyl]-2-morpholinylpropan-1-one (IRGACURE 907, manufactured by Chiba Special Chemical Co., Ltd.), dissolved in 250 parts of isopropyl alcohol The preparation solution (the composition for forming a protective layer) was applied by a bar coating method, and dried by heating in a drying oven at 50 ° C for 1 minute, and then the resulting dried film was subjected to a UV irradiation apparatus (SPOT CURE SP-7). , manufactured by USHIO Motor Co., Ltd., at 400mJ/cm ² The exposure amount of the (365 nm standard) was irradiated with ultraviolet rays to form a protective layer on the polarizing layer, and the same procedure as in Example 1 was carried out. Experimental example: Determination The following physical properties were evaluated for the polarizing plates obtained in the examples and the comparative examples, and the results are shown in Tables 1 and 2. (1) The amount of change in the transmittance was obtained by cutting the polarizing plate obtained in the examples and the comparative examples so that the absorption axis direction was 40 mm and the direction orthogonal to the absorption axis was 40 mm, and the adhesive was applied to the glass plate. sample. The transmittance of the sample was measured in a visible light region using a spectrophotometer (V7100, manufactured by JASCO Corporation). Thereafter, the sample was allowed to stand for 100 hours in a high-temperature drying environment at 85 ° C and in a heating and humidifying environment at 60 ° C and 90% RH, and the transmittance was measured in the same manner. (2) The amount of change in the degree of polarization was obtained by cutting the polarizing plate obtained in the examples and the comparative examples so that the absorption axis direction was 40 mm and the direction orthogonal to the absorption axis was 40 mm, and the sample was prepared by adhering to the glass plate via an adhesive. . The degree of polarization of the sample was measured using a spectrophotometer (V7100, manufactured by JASCO Corporation). Thereafter, the sample was allowed to stand for 100 hours in a high-temperature drying environment at 85 ° C and in a heating and humidifying environment at 60 ° C and 90% RH, and the degree of polarization was measured in the same manner. [Table 1] [Table 2] From Tables 1 and 2, it can be confirmed that the polarizing plate including the polarizer of the present invention has a rate of change of the transmittance and the degree of polarization before and after the placement under conditions of high temperature and/or high humidity of 1.0% or less, and In comparison with Comparative Example 1, the optical properties of the polarizing plate were effectively protected. Moreover, since the protective layer of the non-aqueous composition of the protective layer of Comparative Example 2 was used, it was confirmed that the performance was lowered at the time of completion of the polarizing plate. INDUSTRIAL APPLICABILITY The polarizing plate of the present invention not only has a protective layer composed of a water-based composition, but also has a step of not extending in the production, so that a polarizing plate excellent in durability reliability and having little change in optical characteristics can be realized. Moreover, it can be applied to various display devices to achieve a high level of image quality.

10‧‧‧Adhesive layer
20‧‧‧Protective layer
30a‧‧‧Liquid coating
30b‧‧‧Substrate film
30‧‧‧Polarizer
100‧‧‧Polar plate

Fig. 1 is a cross-sectional view showing a polarizing plate of an example of the present invention.

10‧‧‧Adhesive layer

20‧‧‧Protective layer

30‧‧‧Polarizer

30a‧‧‧Liquid coating

30b‧‧‧Substrate film

100‧‧‧Polar plate

Claims (10)

A polarizing plate is sequentially laminated with an adhesive layer, a protective layer and a polarizer; wherein the protective layer is formed of a water-based composition containing polyvinyl alcohol; and the polarizer is formed on one side of the base film. An alignment liquid crystal coating is imparted by a non-extended method. The polarizing plate of the first aspect of the invention, wherein the polyvinyl alcohol is contained in an amount of from 1 to 10% by weight based on 100% by weight of the total of the aqueous composition. The polarizing plate of claim 1, wherein the protective layer is formed by applying a water-based composition and drying. The scope of the patent polarizer, Paragraph 1, wherein after drying of the protective layer having a thickness of 0.5 ~ 3.0 m m. The polarizing plate of claim 1, wherein the substrate film is a transparent polymer film. The polarizing plate of claim 1, wherein the liquid crystal coating layer comprises a polymerizable liquid crystal compound and a dichroic dye. The polarizing plate of claim 1, wherein the adhesive layer comprises an acrylic copolymer, an epoxy resin, a urethane resin, a decyloxy resin, a polyether resin, a polyester resin, and a polyfluorene. One selected from the group consisting of an amine resin, a polyvinyl alcohol resin, and a combination of these resins. The polarizing plate of claim 1, wherein the polarizing plate is subjected to high temperature or high humidity, and the amount of change in penetration before and after the placement is 1.0% or less. The polarizing plate of claim 1, wherein the polarizing plate is under conditions of high temperature or high humidity, and the amount of change in polarization before and after the placement is 1.0% or less. A display device comprising the polarizing plate according to any one of claims 1 to 9.